The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Cruise control systems control a vehicle cruising speed to maintain a desired cruising speed of a vehicle. The cruise control systems are operatively connected to the vehicle engine and operate the engine automatically in order to maintain the desired cruising speed of the vehicle. Exemplary systems allow a driver to manipulate the cruise control using on/off, set/coast and resume/accelerate switches. The on/off switch enables the driver to turn the cruise control system on or off. The set/coast switch enables the driver to set a vehicle cruising speed in memory or coast while the cruise control system is on. If the cruise control system is on but not operating in cruise control, tapping the set/coast switch sets the vehicle speed in memory at the present vehicle speed and starts the vehicle operating in cruise control. Once the vehicle is operating in cruise control holding the set/coast switch depressed causes the vehicle to coast.
The driver can cause the vehicle to stop operating in cruise control by tapping the brake pedal. The resume/accelerate switch enables a driver to resume to vehicle speed in memory from another speed or accelerate the vehicle speed from vehicle speed in memory while operating in cruise control. For example, if the vehicle was operating in cruise control and the driver brakes, the resume function enables the driver to resume cruise control by automatically accelerating the vehicle back to the vehicle speed in memory. If the vehicle is operating in cruise to maintain the vehicle cruising speed in memory, the driver can hold the resume/accelerate switch depressed to accelerate the vehicle from vehicle speed in memory. Additionally, in exemplary systems the driver can tap the resume/accelerate switch to increase the vehicle speed in memory by one increment, for example, by one mile per hour (MPH) or the set/coast switch to decrease the vehicle speed in memory by one MPH.
Adaptive cruise control (ACC) automatically adjusts vehicle speed to maintain a driver-selected headway from the vehicle ahead in the same lane. The adaptive cruise control system can slow the vehicle down when slow moving traffic is encountered and resume the vehicle to an original set speed when the traffic clears. The adaptive cruise control system uses a ranging sensor to sense traffic ahead, as well as yaw and steering data to determine which targets are in the predicted path of the vehicle.
It is known, for example, to prevent activation of the resume function in adaptive cruise control system when the vehicle is traveling below a threshold low speed range. However, when vehicle speed is the only input, the resume function may be deactivated at undesirable times, such as in stop and go traffic, at stop lights and turning on to a different street. It is therefore desirable to incorporate additional inputs for selectively preventing activation of the resume function in adaptive cruise control systems, so that inappropriate inhibition of the resume function can be avoided or significantly reduced.